Parking gates are well known to the prior art. Thus, by way of illustration, U.S. Pat. No. 3,993,975 of Long et al. claims a parking lot gate which is comprised of (1) electrically operated drive means provided with a first drive means energizing circuit including the contacts of normally deenergized first relay means, (2) normally open first cam switch means coupled to the gate bar and closing in response to the initial operation of the drive means, (3) second relay means controlled by said clearance device, (4) normally closed second cam switch means coupled to the gate bar, (5) a first circuit connected to said first relay means for momentarily energizing same and including the contacts of said second relay means and said normally closed second cam switch means, and (6) a second circuit connected to said first relay means for energizing same and including said first cam switch means.
The parking gate described in the Long et al. patent, in addition to containing relatively complicated electrical circuits, is also mechanically complicated. It is comprised of (1) a down limit switch, (2) an up limit switch, (3) a three-phase alternating current motor, (4) high-current, motor reversal relays, (5) a gear box, (6) belts, (7) two pulleys, (8) a clutch, and (9) linkages to detect the parking gate arm hitting an obstruction.
The Long et al. parking gate is typical of other parking gates commonly used in the industry. It is complicated, expensive, difficult to service, unreliable, and moderately dangerous to service because of the use of relatively high voltage in its electrical circuits.
It is an object of this invention to provide a parking gate which contains substantially fewer parts than prior art parking gates.
It is another object of this invention to provide a parking gate which is substantially more reliable than prior art parking gates.
It is yet another object of this invention to provide a parking gate which has a substantially longer service life than the prior art parking gates.
It is yet another object of this invention to provide a parking gate which does not contain any high-voltage circuitry.
It is yet another object of this invention to provide a parking gate which consumes substantially less energy in its operation than prior art parking gates.
It is yet another object of this invention to provide a parking gate comprised of means for providing more power to the arm of the gate when it is first being raised than later in its raise cycle;
It is yet another object of this invention to provide a parking gate comprised of means for lowering said gate and safety means for limiting the amount of power used in lowering said gate;
It is yet another object of this invention to provide novel means for detecting obstructions which the arm of the parking gate encounters;
It is yet another object of this invention to provide a novel clamp for attaching the arm of the gate to the gate.